Information may be stored on a wide variety of devices. Many data storage devices are quite portable, and thereby subject to theft. Various types of security devices have been proposed in this regard. For instance, many laptops now have a security or locking slot for receiving a lock that is attached to a cable. The lock may be inserted into this slot on the laptop, and the cable may be anchored to an appropriate structure to physically secure the laptop to the anchoring structure.
Physical security of data storage devices is of course an important concern. However, security of the data on such a data storage device is another important concern. Consider the case of an external hard drive that may be interconnected with a computer through a USB cable. If the external hard drive is left unattended, someone could simply connect his or her computer to this external hard drive and obtain data from the external hard drive.